- VARM, a Berlin insulation startup, has raised €17.5 million in a Series A round led by ABN AMRO Sustainable Impact Fund and GET Fund, the firm behind the sonnen battery storage exit to Shell.
- The company insulates a single-family home in one day at a fixed price of around €5,000, with homeowners paying under €4,000 after government subsidies and saving up to 50% on heating costs.
- Founded in 2023 by two serial founders, VARM has completed thousands of projects across seven German cities and is targeting one million insulated buildings across Europe by 2035.
Germany has a plan to retrofit millions of homes. What it does not have is enough people to do it. VARM, a Berlin startup that insulates single-family homes in a single day at a fixed price, has closed a €17.5 million Series A round, with an investor list that includes one of Europe’s most credentialed cleantech venture teams.
GET Fund, formerly Munich Venture Partners, co-led the round alongside ABN AMRO Sustainable Impact Fund, a €500 million vehicle backed by ABN AMRO Bank. GET Fund’s track record includes the exits of sonnen, the home battery storage company acquired by Shell, and Luxexcel, a 3D-printed lens maker acquired by Meta.
Aurum Impact, the impact investing arm of the Goldbeck Family Office, joined as a new investor, alongside returning backers Emerge, Pale Blue Dot, and noa.
“In the next ten years, we must upgrade high-emission buildings to become energy-efficient. The most effective way to do that is through insulation. Scaling in this area is therefore an infrastructure task,” says Christian Grüner, VARM’s co-founder and chief executive.
A logistics problem disguised as a climate problem
The traditional retrofit market in Germany is fragmented and paralysed by a skills shortage. Energy consulting portals broker jobs but do not complete them. General contractors coordinate third parties without building their own delivery capacity. Demand is not the issue, but finding qualified people to do the work, consistently and at scale, is.
Grüner and co-founder Sebastian Würz founded VARM in Berlin in 2023. Both are serial founders: Grüner previously built Vitalon, a longevity-supplement startup; Würz co-founded homefully, a co-living platform that he scaled to Series B before exiting in 2021.
Rather than compete for the scarce pool of certified insulation specialists, VARM trains its own, including career changers from adjacent trades such as painting and drywall installation. Established trade firms join VARM’s partner network, add insulation to their offering, and run jobs on VARM’s AI platform, which handles automated measurement, material calculation, and in-field quality checks at every stage.
The company calls the result a decentralised production infrastructure, which is standardised enough to deliver consistently, flexible enough to scale city by city.
A typical project costs around €5,000. After subsidies from Germany’s federal economics agency, BAFA, homeowners pay under €4,000 out of pocket, cut heating costs by up to 50%, and recoup the full investment within four to seven years. VARM currently operates in seven cities, including Berlin, Hamburg, Bremen, Essen, Cologne, Frankfurt, and Minden, and holds a 4.9-star Google rating based on hundreds of verified reviews.
Since its founding in 2023, it has completed thousands of projects.
Why the execution model matters more than the technology
Julian Klaiber, principal at GET Fund, says that quality holdings at scale were the deciding signal.
“What convinced us was not only how fast VARM is growing, but how consistently stable, scalable, and verifiable quality remains. The team has the right understanding of how proprietary technology, a platform, and AI can be used to support skilled trades. This makes technology a job creator, not a job killer,” he says.
Gaetano Giuffré, investment manager at ABN AMRO Sustainable Impact Fund, whose portfolio includes Fairphone and Converge, frames the thesis in structural rather than technological terms.
“In the retrofit market, demand is not the problem — execution is. VARM trains its insulation specialists itself, building the capacity the market lacks. That takes longer, but it is the more resilient path if a German model is to become European retrofit infrastructure,” he says.
In the German home retrofit market, VARM’s closest comparable is thermondo, Germany’s largest heat pump installer, which has raised over $56 million and was acquired by Brookfield Asset Management. Where thermondo focuses on heating systems, VARM focuses exclusively on insulation, a deliberate bet that the fastest and cheapest lever for cutting household emissions has been consistently overlooked in favour of more complex and expensive technologies.
The regulatory tailwind is significant. The EU’s revised Energy Performance of Buildings Directive, which entered into force in May 2024, requires member states to renovate the worst-performing 16% of non-residential buildings by 2030, rising to 26% by 2033, and mandates national trajectories to reduce average residential energy use. With 85% of EU buildings constructed before 2000 and 75% performing poorly in terms of energy efficiency, and deep renovation rates at only around 1% annually, the compliance gap is enormous, and the deadlines are fixed.
The largest share of the new capital goes into expanding VARM’s partner programme, continued platform development, and geographic expansion across Europe. The company is B Corp-certified and targets one million insulated buildings across the continent by 2035.
“Climate action must not be a luxury project. If we can deliver retrofits at a speed and quality that every homeowner can understand and afford, then insulating one million buildings in Europe by 2035 becomes a question of scaling. The heat transition fails less because of technology than because of execution,” Grüner concludes.
The heat transition has no shortage of ambition or capital. The question is whether VARM’s decentralised, franchise-style delivery model can maintain its quality standards as it expands from seven German cities to a continent, and whether a company built around one-day insulation jobs can become the infrastructure layer that Europe’s retrofit market has been missing.
